By Alex Kirby

Methane emissions are the source of the greenhouse gas which, after carbon dioxide, probably causes climatologists more sleepless nights than any of the other gases. And now it appears they have quite a lot more to bother them than they had realized.

Methane is reckoned to be at least 30 times more powerful than CO2 at warming the earth, with some estimates putting its potency much higher still. The good news, research has suggested, is that there is far less methane than CO2 in the atmosphere to worry about.

The bad news, announced by an international research team, is that previous calculations may have been seriously wrong, and that thawing permafrost is likely to be producing appreciably more methane than anyone had thought.

The researchers were headed by Christian Knoblauch of the Center for Earth System Research and Sustainability(CEN) at…